Huygens' principle (first described by the Dutch scientist Christiaan Huygens in 1678) uses geometry to determine the shape of a wavefront at a time t, given some initial wavefront at an earlier time. This can be constructed by imagining that the initial wavefront is a source of wavelets that propagate from each point at the speed of light. From this principle, one can determine the angles of reflection and refraction by considering the speed of light at each point on the wavefront. In this problem, we will explore some of these concepts.

Explain how tectonic plate movement creates geological events and features.

Jonathan purchases a comic book over the phone. the store does not promise a particular time in which the comic book will be shipped to jonathan. after 40 days, the comic book has not been shipped. do state or federal laws protect jonathan's rights in this case? what is the name of the law? select the best answer from the choices provided. a. federal law; the implied warranty of merchantability b. state law; the implied warranty of merchantability c. federal law; the mail and telephone order rule d. state law; the mail and telephone order rule

Central american countries are important agricultural producers. each year, the united states imports about five billion dollars’ worth of a. bananas b. cacao c. mangoes d. coffee